1. Field of the Invention
The present invention relates to a take-up apparatus for winding an amorphous metal ribbon manufactured through a rapidly rotating quench roll.
2. Prior Art
A method for manufacturing an amorphous metal ribbon includes rapid quenching solidification of molten amorphous material which is facilitated by the heat removing effect of a quench roll after ejecting the molten metal onto the outer circumferential surface of the quench roll which is rotating at a high speed. Since an amorphous metal ribbon can be manufactured at high rates by this method, a high-performance take-up apparatus is required for winding the ribbon, which is manufactured as mentioned above, at a high speed.
Various take-up apparatus have been provided for an amorphous metal ribbon which transport a ribbon within a guide tube by means of a gas blowing means, a shifting magnetic field or a metal conveyer belt and then wind the ribbon up (see Japanese Laid Open Patent Applications No. 1981-99054 and No. 1986-82953). However, there are a number of disadvantages associated therewith. For example, it is impossible to exactly coincide the circumferential speed of the quench roll with that of a take-up drum. Lack of uniformity or breakage of a ribbon is caused when the circumferential speed of the quench roll is lower than that of the take-up drum. It is impossible to wind the ribbon in good order by the take-up drum when the former is higher than the latter and dancing of the ribbon might occur when the ribbon is transported by gas blowing means.
Japanese Laid Open Patent Application No. 1985-246613 discloses a construction where an amorphous metal ribbon manufactured by means of a quench roll is first transported into a storage device. However, since the winding and stopping of the ribbon is repeated intermittently so that the ribbon can be taken up directly by a take-up frame comprising a plurality of steel cores, the storage device becomes very large in size. Further, since the ribbon is adapted to be brought into the storage device by a gas blowing means, disadvantageous ribbon dancing as well as ribbon entanglements are apt to occur.
A grasp and cut technology in which the fore part of the ribbon is grasped and the leading end portion beyond the grasped portion of the fore part is cut off before carrying out the ribbon winding is disclosed in Japanese Laid Open Patent Application No. 1978-24961. That is in order to grasp and cut the ribbon, a take-up drum is provided on its take-up surface with an axial recess and a gripping lever is pivotably mounted on its side portion so as to project and fit in the recess. However, the complicated construction is a disadvantage. Additionally as a means for compensating for the differences in the circumferential speeds of a quench roll and of the take-up drum, a vertically movable roller is provided therebetween. However since the vertical movement of the roller is accompanied by an inertia force, the ribbon is subjected to an excessive tension force due to the inertia of the roller when a quantity of the stored ribbon is changed over from an increasing trend to a decreasing trend and to the contrary, the ribbon is not subjected to tension when a quantity of the stored ribbon is changed over from a decreasing trend to an increasing trend. In the latter case, since there is a problem similar to that caused by the disagreement in the circumferential speeds of the quench roll and of the take-up drum, it is impossible to wind the ribbon under a constant tension.